New paper: "Security Analysis of Pseudo-Random Number Generators with Input: /dev/random is not Robust, by Yevgeniy Dodis, David Pointcheval, Sylvain Ruhault, Damien Vergnaud, and Daniel Wichs.

Abstract: A pseudo-random number generator (PRNG) is a deterministic algorithm that produces numbers whose distribution is indistinguishable from uniform. A formal security model for PRNGs with input was proposed in 2005 by Barak and Halevi (BH). This model involves an internal state that is refreshed with a (potentially biased) external random source, and a cryptographic function that outputs random numbers from the continually internal state. In this work we extend the BH model to also include a new security property capturing how it should accumulate the entropy of the input data into the internal state after state compromise. This property states that a good PRNG should be able to eventually recover from compromise even if the entropy is injected into the system at a very slow pace, and expresses the real-life expected behavior of existing PRNG designs. Unfortunately, we show that neither the model nor the specific PRNG construction proposed by Barak and Halevi meet this new property, despite meeting a weaker robustness notion introduced by BH. From a practical side, we also give a precise assessment of the security of the two Linux PRNGs, /dev/random and /dev/urandom. In particular, we show several attacks proving that these PRNGs are not robust according to our definition, and do not accumulate entropy properly. These attacks are due to the vulnerabilities of the entropy estimator and the internal mixing function of the Linux PRNGs. These attacks against the Linux PRNG show that it does not satisfy the "robustness" notion of security, but it remains unclear if these attacks lead to actual exploitable vulnerabilities in practice. Finally, we propose a simple and very efficient PRNG construction that is provably robust in our new and stronger adversarial model. We present benchmarks between this construction and the Linux PRNG that show that this construction is on average more efficient when recovering from a compromised internal state and when generating cryptographic keys. We therefore recommend to use this construction whenever a PRNG with input is used for cryptography.

A number of prominent international speakers will discuss your right to information self-determination, the politics of privacy, how to deal with the secret cosmopolitan state within a state, and how to go forward. It is a congress of individuals to represent what is not (yet?) represented by institutions.

Back in June, when the contents of Edward Snowden's cache of NSA documents were just starting to be revealed and we learned about the NSA collecting phone metadata of every American, many people -- including President Obama -- discounted the seriousness of the NSA's actions by saying that it's just metadata.

Lots and lots of people effectively demolished that trivialization, but the arguments are generally subtle and hard to convey quickly and simply. I have a more compact argument: metadata equals surveillance.

Imagine you hired a detective to eavesdrop on someone. He might plant a bug in their office. He might tap their phone. He might open their mail. The result would be the details of that person's communications. That's the "data."

Now imagine you hired that same detective to surveil that person. The result would be details of what he did: where he went, who he talked to, what he looked at, what he purchased -- how he spent his day. That's all metadata.

When the government collects metadata on people, the government puts them under surveillance. When the government collects metadata on the entire country, they put everyone under surveillance. When Google does it, they do the same thing. Metadata equals surveillance; it's that simple.

It turns out that the NSA's domestic and world-wide surveillance apparatus is even more extensive than we thought. Bluntly: The government has commandeered the Internet. Most of the largest Internet companies provide information to the NSA, betraying their users. Some, as we've learned, fight and lose. Others cooperate, either out of patriotism or because they believe it's easier that way.

And welcome to a world where all of this, and everything else that you do or is done on a computer, is saved, correlated, studied, passed around from company to company without your knowledge or consent; and where the government accesses it at will without a warrant.

All disruptive technologies upset traditional power balances, and the Internet is no exception. The standard story is that it empowers the powerless, but that's only half the story. The Internet empowers everyone. Powerful institutions might be slow to make use of that new power, but since they are powerful, they can use it more effectively. Governments and corporations have woken up to the fact that not only can they use the Internet, they can control it for their interests. Unless we start deliberately debating the future we want to live in, and the role of information technology in enabling that world, we will end up with an Internet that benefits existing power structures and not society in general.

The whole concept of security awareness training demonstrates how the computer industry has failed. We should be designing systems that won't let users choose lousy passwords and don't care what links a user clicks on. We should be designing systems that conform to their folk beliefs of security, rather than forcing them to learn new ones. Microsoft has a great rule about system messages that require the user to make a decision. They should be NEAT: necessary, explained, actionable, and tested. That's how we should be designing security interfaces. And we should be spending money on security training for developers. These are people who can be taught expertise in a fast-changing environment, and this is a situation where raising the average behavior increases the security of the overall system.

If we security engineers do our job right, users will get their awareness training informally and organically, from their colleagues and friends. People will learn the correct folk models of security, and be able to make decisions using them. Then maybe an organization can spend an hour a year reminding their employees what good security means at that organization, both on the computer and off. That makes a whole lot more sense.